YAML formatting

Can't find a definite answer to this anywhere so I have to ask here: how do I make IntelliJ format yaml?

I've just converted over my maven pom.xml to pom.yml so I need it now and unlike the properties files, this is going to require a lot of indenting.

However I want to change the default indent from 2 spaces to 4 and when I change it in the Settings->Editor->Code Style->YAML, it has no effect.

I tried installing the Snake YAML plugin and it says in its notes that the default YAML setting for file extensions has to be changed to take over the .yml extensions - so implying that native IntelliJ should format YAML???

I saw a bug on youtrack showing that formatting for YAML was still an open issue so I'm a bit pessimistic about this.

https://youtrack.jetbrains.com/issue/RUBY-2185

OK, so it is for RUBY but I suspect if you have YAML formatting for one thing, you would re-use it everywhere.

However there is a large chance I am suffering from temporary cerebral aphasia (non-heriditary stupidity) - because I do this and get zero results:

- go to Settings -> Editor -> Code Style -> YAML

- change "Indent" field to 4 & apply

- open file with 2-space indents

- press ctrl-alt-L

- get small advice pop-up "No lines changed: content is already properly formatted"